You HAVE to know the stack sizes. It makes a difference whether you start with 30BB or 300BB. Has no one here read The Bible? (I mean Reuben/Ciaffone.)
If everytime you got dealt KK & regardless of your opponent you tried to get all your stack in the middle pre-flop and succeeded. Would this be a + EV play ?
You have asked the wrong question. Currently, you are asking "Would it be +EV if, every time you got dealt KK, your opponent magically went all-in?". Of course it would. (I'm assuming that when you say 'succeeded' you mean 'succeeded to get a call'.)
I think the question you meant to ask was: "If my opponent moves all-in preflop and I have KK, would it be +EV to always call regardless of who he was?". Of course it wouldn't. Proof: imagine you are playing against a player who only play Aces. QED.
By the way, excellent use of italics and bold.